Telephone receiver



Sept. 23, 1924. 1,509,805

H. P. DONLE TELEPHONE RECEIVER Filed April 25, 1922 I mu 0 Patented Sept. 23, 1924.

UNITED STATES PATENT OFFICE.

HAROLD P. DONLE, OF MERIDEN, CONNECTICUT, ASSIGNOR TO THE CONNECTICUT TELEPHONE & ELECTRIC COMPANY, INC, 013 MERIDEN, CONNECTICUT, A COR- PORATION OF CONNECTICUT.

TELEPHONE RECEIVER.

Application filed April 25, 1822. Serial No. 556,402.

To all who-72L. it may concern Be it known that I, HAROLD 1 Donna, a citizen of the United States of America, residing at Meriden, Connecticut, have invented a new and useful Telephone Receiver, of which the following is a specification.

The main object of my invention is to provide a simple, efficient, sensitive receiver which can be made economically. One specific object is to mount the magnet in the casing in such a manner that it is unneces sary to drill the magnet.

Another object is to construct the parts so that they may be readily assembled or taken apart.

Another object is to ensure clear reproduction of sound.

In the form shown the magnet and coils are clamped in the casing by a plate and screws which pass through the plate between the coils and the ends of the permanent magnet. The parts are so constructed and arranged that there is a minimum air space behind the diaphragm and as a consequence only a minimum free, as contrasted to controlled vibration of the diaphragm, is permitted.

Fig. 1 is a. front view of the receiver embodying the improvements of my invention the ear piece or cap being removed.

Figs. 2 and 3 are sectional views at right angles to each other with the ear piece in place.

Fig. 4 is a perspective view showing the magnet, pole pieces and clamping plate.

A casing 5 may be of any suitable construction, to which is attached in any suitable manner an ear piece or cap 6.

Inside the casing is mounted a permanent magnet 7. The pole pieces 8 and 9 may be formed of softer metal having feet beneath the ends of the magnet. Coils 10 and 11 are supported on these pole pieces between the opposite sides of the magnet.

A plate 12 rests on the heads of the coils and on the outer edge of the magnet and is held in place by screws such as 13 and 14 which pass into the back of the casing. In this way it is possible to hold the magnet securely in position without drilling into the hardened steel. The screws may pass through holes in the feet of the pole pieces and thus accurately position the pole pieces.

Lugs 12 may be formed on the ends of the U-shaped plate 12 to more securely hold the magnet from shifting.

In one side of the casing opposite the ends of the magnet and adjacent the ends of the coils I mount an insulating block 15 which carries the circuit terminals 16 and 17 and the binding screws 18 and 19. This block may be held in place by a screw 20.

The diaphragm 21 is clamped in place by the ear piece which holds it against the edge of the casing. The plate 12 being located close to the diaphragm leaves but little air space behind the diaphragm. This results in a damping effect on the action of the diaphragm and prevents free vibration which would tend to interfere with accurate reproduction of sound.

The plate 12 thus in this instance performs the double function of clamping the magnet and damping the action of the dia phragm.

The parts are so constructed that they may be economically made and assembled. The pole pieces are preferably made of soft iron blanked and shaped and provided with the necessary coils. The horeshoe part of the magnet is preferably formed of bar steel shaped as desired and then suitably hardened. I

In assembling the parts the pole pieces and coils are first inserted in the casing and then the permanent magnet part laid over the feet of the pole pieces. The plate 12 is then laid in the casing and clamped down by the screws 13 and 14: which pass through the feet of the pole pieces between the coils and the ends of the horseshoe. The block 15 may be inserted at any convenient time in the process of assembly. It not only serves to support the circuit terminals but as it approximately fills that part of the casing which is not covered by the plate 12, it reduces the volume of air in the casing and contributes to the damping of the free vibration of the diaphragm.

I claim:

1. In a telephone receiver, a casing, a- U-shaped magnet therein having pole pieces and coil windings, a U-shaped plate overlying said magnet and said coil windings, and means for holding said plate and said magnet and windings in place.

2. In a telephone receiver a casing, 21

U-shaped magnet therein having pole pieces and coil windings, a- U-shaped plate overlying said magnet and said coil windings, means for holding said plate and said magnet and windings in place, said plate having lu s bent over at the ends of said magnet to prevent said magnet from shifting in said casing.

3. In a telephone receiver, a casing, a magnet angular pole pieces therefor having coil windings a clamping plate overlying the edge of said magnet and engaging the heads of said coil windings and screws passing through said plate to hold it in said casing.

4. In a telephone receiver, a casing, a U-shaped magnet, pole pieces and coils therefor, an anchorage plate overstanding said magnet and the heads of said coils, and means for clamping said magnet and coils between said plate and said casing.

5. In a telephone receiver a casing, a U-shaped magnet therein having pole pieces and coil windings and means entirely outside of said magnet including a U-shaped plate for clamping said coil windings and the ends of said magnet in said casing.

6. In a telephone receiver, acasing, a U-shaped magnet therein having coil windings, a U-shaped plate overstanding said magnet and having end lugs for preventing lateral displacement of said magnet and means independent of said magnet for securing said plate to said casing.

HAROLD P. DONLE. 

